Method of utilizing the gases resulting from reduction operations carried out in electric furnaces, and electric furnaces for carrying out the same.



I A. HELPENSTEIN. METHOD OF UTILIZING THE GASES RESULTING FROM REDUCTIONOPERATIONS CARRIED OUT IN ELECTRIC PURNACES,AND ELECTRIC FURNACES FORCARRYING OUT THE SAME.

APPLICATION EILEI) NOV.16, 1909. RENEWED JULY 25, 1911. 1 02,988.

Patented Sept. 12, I911.

J7 W n/M Z? I y f v ark/12% UNITED STATES PATENT orrioa.

ALOIS HELFENSTEIN, OF VIENNA, AUSTRIA-HUNGARY.

METHOD OF UTILIZING THE GASES RESULTING FROM REDUCTION OPERATIONSCARRIED OUT IN ELECTRIC FURNACES, AND ELECTRIC FURNACES FOR CARRY- INGOUT THE sAME.

Patented Sept. 12, 1911.

Application filed November 16, 1909, Serial No. 523,381. Renewed July25, 1911, Serial No. 640,529.

T 0 all whom it aria-y concern:

Be it known that I, Errors llnmu-zxs'rnm, a citizen of the Republic ofSwitzerland, residing at No. at Pokornigasse XIX, Vicnna, in the Empireof Austria-Hungary, have invented certain new and useful impro vementsin methods of utilizing thegases resulting from reduction operationscarried out in electric furnaces, and electric furnaces .for carryingout the same, of which the following is a specification.

Various attempts 'have'been made to utilize the large quantities ofcombustible gases which are generated during reduction processes inelectric furnaces. burned in the mixture or in a: special constituent ofthe mixture in the furnace itself or in the charging shaft, in order topreliminarily heat the mixing n'raterial. and finally, the gases aredrawn oil by suction and conveyed away for the purpose of being usedelsewhere and not directly for the furnace process. This manner ofconsuming the generated gases is however attended with disadvantages,among which, is the fact that the air cannot be conveyed so that thereis not from time to time a combustion of the carbon, which is intendedforreduction purposes only. and thus interfering with the furnace prcess.

The object of the present invention is to obviate these disadvantages,and to provide a method and apparatus for carrying out said method,whereby the generated gases are consumed outside of the furnace charge,but within the furnace reduction chamber.

To this end the invention further consists in providing a free portionof the reduction chamber, limited by the sides of the furnace and by theinclined sides of the charge of material, in which spade the gases areburned.

In carrying outthe. r ethod forming the present invention, lime andcoal, for example, (when it is desired to produce calcium carbid) areintroduced into a charging shaft around the vertical electrodes arrangedin said charging shaft, said charging shaft being of relatively small.diamc'lcr or cross section and arranged above a reduction chamber ofrelatively larger dimensions. The mixture fed into the upper chamber orcharging shaft at first passes into the lower These gases are orreduction chamber, where it spreads out in said enlarged reductionchamber so as to form an approximately conical shaped charge, whereby alarge space is formed between the inclined sides of said conical shapedcharge and the sides of the furnace, affording a combustion chamber forthe gases generated during the reduction process. The relatively narrowcharging shaft, which as above mentioned receives the electrode, is madegas-tight at its upper portion, so that gases generated during the reduction of the mixture surrounding the electrode are made to pass intothe combustion space located in the reduction chamber.

3* feature of my invention consists in that, when the material ischarged into the charging shaft and reduction chamber, it is fed in sucha quantity that the material fills, or nearly fills, said chargingshaft, so as to completely inclosc and surround the electrode. Into thecombustion space of the reduction chamber, air is blown or otherwisesuitably drawn, whereby the gases generated during the reduction processmay be con sumed, and the material constituting the mixture to bereduced may be preliminarily and suitably heated immediately beforeontering the melting zone. This preliminary heating of the material iseffected by its direct contact with the flames produced by thecombustion of the gaseous mixture. and by radiated neat. The products ofcombustion may be drawn off from the combustion chamber sidcwise orupwardly, and conveyed away for the purposes of future use.-

My invention may be carried out by means of the apparatus shown invertical section in the accompanying drawing.

In the electric furnace shown in said drawing, the reference character arepresc'nts the charging shaft, which may be of cylindrical shape, orsquare shape, and is of relatively small diameter compared to .thereduction chamber hereinafter described. The charging shaft 0 isprovided with a gas-tight cover 7) on its upper portion and at its lowerend opens into the furnace reduction chamber c. The said reductionchamber may be of either cylindrical or v quare shape, and may beapproximately rectangular in cross section and it is relatively large ascompared with the charging shaft, as will be seen upon reference to thedrawing. The reduction chamber is provided at its top with a fire-proof,gas-tight covering, (Z, in which are formed the openings or slots 6. Forthe purpose of admitting the air used for the combustion of the gasesgenerated during the melting of a charge, an opening f is provided inone of the side walls of the reduction chamber, so that the .air may beblown or drawn directly into the combustion space for the gases. Asbefore stated the products of combustion may be withdrawn from thechamber either sidewise or upwardly, but in the drawing I have shown apipe f disposed in one of the side walls of the furnace by means ofwhich the said products of combustion may pass away. In the middle ofthe charging shaft is arranged an upper vertical electrode 9 while alower electrode 9 is arranged in the bottom wall of the furnace, saidelectrode being disposed preferably in a horizontal position as shown.The charge is effected in such a manner that the electrode 9 issurrounded by the mixture tobe reduced.

It will thus be seen from the structural arrangement shown in thedrawing that a cylindrical shaped charge contained in the chargin shaftand surrounding the electrodeg is connected directly at zone It with anapproximately conical shaped charge contained in the reduction chamber0, the structure being such' that the material fed into the reductionchamber assumes such approximately conical shape and provides a spacebetween the inclined sides of the conical charge and the walls of thereduction chamber, said space serving as a combustion chamber 2' intowhich the gases generated during the reduction process areforced out ofthe mixture, and where they are burned by the introduction of asupply ofair. This space 2' is thus brought to a white heat and the mixturecontinuously fed down from the charging shaft is preliminarily heated inthis zone immediately after its entrance into the reduction chamber.mixture outof the narrower shaft is pro- -moted by the upward anddownward movement of the electrode when the regulating thereof iseffected. The electrode is always kept covered or surrounded by thematerial and thus protected from damage against the hotgases.

' Besides the furnace gases, combustible gases from outside sources maybe introduced into the space 2' through the openings f for thepurposeofpromoting the combustion, and to what extent this is necessary may bedetermined by observing the reduction process, which is made possible bymeans'of the slots e. These slots also enable air to be introduced intothe previously heated combustionchamber in carrying out the presentmethod. The charging shaft The conveyance of the may be narrowed at thebottom in order to reduce the upper cross section of the conical shapedcharge of material.

1. The herein described method ofv utilizing the gases resulting fromreduction operations carried out in electric furnaces, which consists inintroducing a charge of material into the furnace in such a manner thatthe charge assumes an approximately conical shape and at the same timeprotect- 1 ing and surrounding the upper electrode of the furnace bymeans of freshly fed material, and providing a space about the conicalshaped charge into which gases gen erated during the reaction aredlscharged, melting the said charge of material and allowing thegenerated gases to discharge into the said space, and admitting air intosaid space so that it may mingle with the said gases and cause'their,combustion, whereby the material 'freshl fed into the electric furnacemay be pre iminarily heated in the upper zones of the conical shapedcharge of material.

2. The herein described method of utilizing the gases resulting fromreduction operations carried out in electric furnaces,

which consists in introducing a charge of.

material into the furnace in such a manner that the charge assumes anap.oximately conical shape and at the same'tlme'protecting and surroundingthe upperelectrode of the furnace by means of freshly fed material, andprovidin a space about the conical shaped charge into which gasesgenerated during the reaction are discharged, melting the said charge-of.material and allowing the generated gases to discharge into the saidspace, and mitting air and combustible gases into sai space so that theair may min le with the said gases and cause their com ustion, wherebythe material freshly fed into the electric furnace may be preliminarilyheated in the upper zones of theconical shaped charge of Inarangementbeing such that a charge of material into the furnace may surround thesa1d electrode and may assume an approxinto the interior of saidreduction chamber.

5. An electric furnace having a reduction chamber of relatively largediameter and a charging shaft arranged above said reduction chamber andopening thereinto, said charging shaft having a relatively smalldiameter as compared with said reduction chamber, a vertical electrodepassing through said charging shaft, a gas-tight cover for the upperportion of said charging shaft, the arrangement being such that a chargeof material into the furnace may surround the said electrode and mayassume an approxi mately conical shape in the reduction chamher so thata combustion space for gases may be formed within the reduction chamberbetween the sides of the conical shaped charge and the walls of thereduction chamher, and air inlet openings arranged to deliver airintothe interior of said reduction chamber.

In testimony whereof I affix my signature in presence of two witnesses.

ALOIS HELFENSTEIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, D. C.

